Gas-phase reactor and system having exhaust plenum and components thereof

ABSTRACT

An improved exhaust system for a gas-phase reactor and a reactor and system including the exhaust system are disclosed. The exhaust system includes a channel fluidly coupled to an exhaust plenum. The improved exhaust system allows operation of a gas-phase reactor with desired flow characteristics while taking up relatively little space within a reaction chamber.

FIELD OF INVENTION

The present disclosure generally relates to gas-phase reactors andsystems. More particularly, the disclosure relates to gas-phase reactorexhaust systems, to reactors and systems that include the exhaustsystem, and to components thereof.

BACKGROUND OF THE DISCLOSURE

Gas-phase reactors, such as chemical vapor deposition (CVD),plasma-enhanced CVD (PECVD), atomic layer deposition (ALD), and the likecan be used for a variety of applications, including depositing andetching materials on a substrate surface. FIG. 1 illustrates a typicalgas-phase reactor system 100, which includes a reactor 102, including areaction chamber 104, a susceptor 106 to hold a substrate 130 duringprocessing, a gas distribution system 108 to distribute one or morereactants to a surface of substrate 130, one or more reactant sources110, 112, and optionally a carrier and/or purge gas source 114, fluidlycoupled to reaction chamber 104 via lines 116-120 and valves orcontrollers 122-126. System 100 also includes a vacuum source 128.

Often, particularly when precise control of deposition or etch processesare desired, the gas distribution system and the reactor exhaust systemare configured to provide laminar flow and/or uniform velocity ofreactants over the surface of substrate 130. To do this, system 100includes an annular exhaust plenum 132 ring around a boundary ofreaction chamber 104. Plenum 132 can include gaps or holes to obtain adesired pressure differential around a perimeter of substrate 130 andsusceptor 106, which allows a single fluid connection between plenum 132and vacuum source 128, while providing laminar flow across the surfaceof substrate 130.

Although the plenum design of system 100 works relatively well, thedesign has drawbacks. For example, plenum 132 occupies significantreaction chamber 104 space. In addition, the reactor design requiresthat substrates 130 are loaded into or unloaded out of reaction chamber104 by moving susceptor 106 relative plenum 132 (e.g., downward) toprovide access to a load/unload area away from plenum 132. Systems thatrequire movement of susceptor 106 to provide access to a load/unloadregion within reactor 102 are relatively complex and expensive. Inaddition, additional internal chamber volume is generally required forsystems that include a moving susceptor, which in turn can lead toincreased gas consumption and lower throughput times due to increasedpumping, backfill, and purge times. The significant amount of areawithin reaction chamber 104 that plenum 132 and/or a moving susceptoroccupies further adds to the cost of system 100.

Accordingly, improved gas-phase reactor exhaust systems and plenums,which occupy less reaction chamber space, and/or reactors and systemsthat don't require movement of a susceptor for loading and unloadingsubstrates, are desired.

SUMMARY OF THE DISCLOSURE

Various embodiments of the present disclosure relate to gas-phasereactors and systems and to improved exhaust systems and plenums for thegas-phase reactors and systems. While the ways in which variousembodiments of the present disclosure address drawbacks of priorgas-phase reactors, systems, and exhaust systems are discussed in moredetail below, in general, various embodiments of the disclosure providean improved exhaust and plenum design for gas-phase reactors, whichallow for less complex, less expensive, higher throughput reactor andsystem designs.

In accordance with exemplary embodiments of the disclosure, a gas-phasereactor includes a reaction chamber comprising a top surface, a bottomsurface, a sidewall, and an interior region formed between the topsurface, the bottom surface, and the sidewall; a susceptor within theinterior region, the susceptor comprising a side perimeter; a channelformed between the side perimeter and the sidewall; and an exhaustplenum within the interior region and beneath the susceptor, the exhaustplenum fluidly coupled to the channel. In accordance with variousaspects of these embodiments, the channel is configured to control gasflow over a surface, such as a surface of a substrate during process, byrestricting a gas flow to the plenum. To achieve this, the channel canextend about the entire susceptor side perimeter. Exemplary channelwidths are greater than 0 mm and less than about 4 mm, or about 0.5 mmto about 4 mm, or about 2 mm. In accordance with further aspects ofthese exemplary embodiments, the reactor includes a vacuum source (e.g.,low-vacuum pump or a dry pump) and optionally a control valve to controla pressure in the reaction chamber. The reactor can also include anauxiliary pump, such as a turbomolecular pump or turbopump forlower-pressure processing. In accordance with further exemplary aspects,the reaction chamber sidewall includes an opening (e.g., above, level,or including an area level with a top surface of the susceptor) toreceive a substrate for processing. The plenum resides below thesusceptor to reduce an amount of active reaction chamber space that theplenum may otherwise occupy. The plenum can include any suitable shape,such as a substantially hollow cylinder, a toroid, a hollow square, ahollow rectangle, or the like. By way of example, the plenum can be ahollow cylinder having height of about 2 to about 25 mm or about 10 toabout 20 mm, and outside diameter of about 334 to about 374 mm, and ininside diameter of about 79 to about 99 mm.

In accordance with additional exemplary embodiments of the disclosure, agas-phase reactor exhaust system includes a plenum having a top portioncomprising a bottom portion of a susceptor and a bottom portioncomprising an interior bottom surface of a reaction chamber; a channelformed between the susceptor and an interior surface of a reactionchamber, the channel fluidly coupled to the plenum; and a vacuum sourcefluidly coupled to the plenum. In accordance with various aspects ofthese embodiments, the channel width is greater than 0 mm and less thanabout 4 mm, or about 0.5 mm to about 4 mm, or about 2 mm. The channelcan extend about the entire perimeter of the susceptor to providelaminar flow in a radial direction across a substrate. The plenum caninclude any suitable shape, such as those noted above.

In accordance with yet additional exemplary embodiments of thedisclosure, a gas-phase reactor system includes a gas-phase reactor asdescribed herein, a vacuum source coupled to a plenum within thereactor, and one or more gas sources.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A more complete understanding of exemplary embodiments of the presentdisclosure may be derived by referring to the detailed description andclaims when considered in connection with the following illustrativefigures.

FIG. 1 illustrates a prior-art gas-phase reactor system.

FIG. 2 illustrates a cut-away view of a gas-phase reactor and exhaustplenum in accordance with exemplary embodiments of the disclosure.

FIG. 3 illustrates another cut-away view of the reactor and exhaustplenum illustrated in FIG. 2.

It will be appreciated that elements in the figures are illustrated forsimplicity and clarity and have not necessarily been drawn to scale. Forexample, the dimensions of some of the elements in the figures may beexaggerated relative to other elements to help to improve theunderstanding of illustrated embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE DISCLOSURE

The description of exemplary embodiments of reactors, components, andsystems provided below is merely exemplary and is intended for purposesof illustration only; the following description is not intended to limitthe scope of the disclosure or the claims. Moreover, recitation ofmultiple embodiments having stated features is not intended to excludeother embodiments having additional features or other embodimentsincorporating different combinations of the stated features.

The present disclosure generally relates to gas-phase reactors, systemsincluding the reactors, and to exhaust systems and plenums for thereactors. As set forth in more detail below, the reactors and systemsinclude an exhaust plenum that resides underneath, rather than coplanarwith a substrate to be processed. This allows the plenum to take up lessactive area within a processing area of the reactor, and for a lesscomplex, less expensive reactor design and operation costs.

FIGS. 2 and 3 illustrate a reactor 200 in accordance with exemplaryembodiments of the disclosure. Reactor 200 includes a reaction chamber202, a susceptor 204, a channel 206, and an exhaust plenum 208 (alsoreferred to herein as plenum region or simply plenum). In theillustrated example, reactor 200 also includes a gas distribution system210, such as a shower head.

Reactor 200 can be any suitable gas-phase reactor. For example, reactor200 can be a chemical vapor deposition (CVD) reactor, a plasma-enhanceCVD (PECVD) reactor, an atomic layer deposition (ALD) reactor, anepitaxial reactor, or the like. By way of example, reactor 200 is anetch reactor for removing native or thermal silicon oxide.

Reaction chamber 202 includes a top surface 242, a bottom surface 244, asidewall 228, and an interior region 245 formed between top surface 242,bottom surface 244, and sidewall 228. As illustrated, reaction chamber202 can include an opening 302 in sidewall 228 to receive asubstrate—e.g., from an automatic loader—which can be placed ontosusceptor 204, without requiring movement of susceptor 204.

Susceptor 204 is located within interior region 245. Susceptor 204 isconfigured to receive and retain a substrate 212 in place duringprocessing, such as during a deposition or etch process. Exemplarysusceptor 204 includes a recess 214 to receive substrate 212, such thata top surface of substrate 216 is substantially coplanar with a topsurface of the susceptor 218. This allows substantially laminar flowand/or uniform velocity across the surface of the substrate 216 and thesurface of the susceptor 218. Susceptor 204 can also include temperaturemeasurement devices 220, 222 and/or heating elements 224. Use of heatingelements allows reactor 202 to operate in a cold wall/hot substrate modeto reduce undesired deposition or etch on walls of reaction chamber 202.Exemplary susceptors, suitable for susceptor 204 are described in moredetail in U.S. application Ser. No. ______ entitled “REMOVABLE SUBSTRATETRAY AND ASSEMBLY AND REACTOR INCLUDING THE SAME”, filed Mar. 19, 2014,the contents of which are incorporated herein by reference, to theextent such contents do not conflict with the present disclosure.

In accordance with various examples of the disclosure, susceptor 204 isfixedly attached to reactor 200 and does not move relative to reactionchamber 202 to receive or allow removal of substrate 212. This allows asimplified, less expensive design of reactor 202 compared to similarreactors. In addition, because less interior reaction chamber volume isused, operating costs of reactors including the improved plenum arereduced.

Channel 206 provides fluid communication between reaction chamber 202and plenum 208. In accordance with exemplary aspects of the illustratedembodiments, channel 206 is about an entire perimeter of a side 226 ofsusceptor 204—e.g., channel 206 forms an annular region between sidewall228 and side 226. This configuration facilitates laminar flow in aradial direction across substrate 212 and susceptor 204. Channel 206 canoptionally include a boss and/or inserts to further control flow ofgasses across surfaces 216 and 218. Additionally or alternatively, awidth of the channel (the spacing between side 226 and a side ofreaction chamber 228) can vary to provide a desired flow across surfaces216, 218. For example, the channel can include a narrow width in an areanear a vacuum source 230 and include a relatively wide width away fromvacuum source 320. A width of the channel can range from greater than 0mm to about 4 mm, about 0.5 mm to about 4 mm, or be about 2 mm. Inaccordance with yet further examples, the width can taper from topsurface 218 to a bottom surface of the susceptor 232. In this case, thewidth can taper from wide to narrow or from narrow to wide.

Illustrated exhaust plenum 208 is located beneath susceptor 204. Thisallows desired gas exhaust, using less active reaction chamber 202volume, and allows loading and unloading of substrates onto susceptor204, without requiring movement of susceptor 204. Plenum 208 can beformed of a variety of shapes, such as a substantially hollow cylinder,a toroid, a hollow square, a hollow rectangle, or the like. Thedimensions of plenum 208 can depend on a type and/or size of reactor200. By way of examples, a height, H, of plenum 208 can range fromgreater than 0 mm to about 15 mm, about 5 mm to about 25 mm, about 10 toabout 20 mm, or be about 15 mm, an outside diameter can range from about334 to about 374 mm or be about 354 mm, and in inside diameter can rangefrom about 79 to about 99 mm or be about 89 mm. Plenum 208 is fluidlycoupled to vacuum source 230, such as a vacuum pump (e.g., a low-vacuumor dry vacuum pump), and optionally to an auxiliary pump 234, such as aturbomolecular pump or turbopump. A control valve 246 can be fluidlycoupled to plenum 208 to control a pressure in plenum 208 and/or withinreaction chamber 202.

In the illustrated example, plenum 208 is formed within, e.g., machinedfrom, reactor 202. In this case, no additional parts are required toform plenum 208.

As noted above, gas distribution system 210 can suitably include ashowerhead. Showerhead gas distribution systems enable uniformdeposition and etch processes across surface of substrate 216. Gasdistribution system 210 includes a plate 236 having perforations orholes 238 formed therein and an open area 240, where, for example,precursor gasses or reactant and carrier gasses can mix. Area 240 can bea plasma chamber for gas-phase reactions with use of a remote plasma. Inthe case of direct plasma reactors, gas distribution system 210 can forman electrode to generate a plasma within reaction chamber 202. Whetherpart of a direct plasma system or not, gas distribution system 210 canbe located within reaction chamber 202.

Although exemplary embodiments of the present disclosure are set forthherein, it should be appreciated that the disclosure is not so limited.For example, although the systems, reactors, and components aredescribed in connection with various specific configurations, thedisclosure is not necessarily limited to these examples. Variousmodifications, variations, and enhancements of the system and method setforth herein may be made without departing from the spirit and scope ofthe present disclosure.

The subject matter of the present disclosure includes all novel andnonobvious combinations and subcombinations of the various reactors,systems, components, and configurations, and other features, functions,acts, and/or properties disclosed herein, as well as any and allequivalents thereof.

We claim:
 1. A gas-phase reactor comprising a reaction chambercomprising a top surface, a bottom surface, a sidewall, and an interiorregion formed between the top surface, the bottom surface, and thesidewall; a susceptor within the interior region, the susceptorcomprising a side perimeter; a channel formed between the side perimeterand the sidewall; and a plenum within the interior region and beneaththe susceptor, the plenum fluidly coupled to the channel.
 2. Thegas-phase reactor of claim 1, wherein a width of the channel is greaterthan 0 mm and less than 4 mm.
 3. The gas-phase reactor of claim 1,wherein a width of the channel is between about 0.5 mm to about 4 mm. 4.The gas-phase reactor of claim 1, further comprising a vacuum sourcefluidly coupled to the plenum.
 5. The gas-phase reactor of claim 4,further comprising a control valve fluidly coupled between the vacuumsource and the plenum.
 6. The gas-phase reactor of claim 1, wherein thesusceptor is stationary during substrate loading.
 7. The gas-phasereactor of claim 1, wherein the sidewall comprises an opening to receivea substrate to be placed on a top surface of the susceptor.
 8. Thegas-phase reactor of claim 1, further comprising a turbomolecular pumpfluidly coupled to the plenum.
 9. The gas-phase reactor of claim 1,further comprising a showerhead gas distribution system within thereaction chamber.
 10. The gas-phase reactor of claim 1, wherein thechannel defines an annular region between the susceptor and thesidewall.
 11. The gas-phase reactor of claim 1, wherein the plenum isformed within a bottom portion of the reaction chamber.
 12. Thegas-phase reactor of claim 1, wherein a shape of the plenum issubstantially a hollow cylinder.
 13. A gas-phase reactor exhaust systemcomprising: a plenum having a top portion comprising a bottom portion ofa susceptor and a bottom portion comprising an interior bottom surfaceof a reaction chamber; a channel formed between the susceptor and aninterior surface of a reaction chamber, the channel fluidly coupled tothe plenum; and a vacuum source fluidly coupled to the plenum.
 14. Thegas-phase reactor exhaust system of claim 13, wherein the channelcomprises a width greater than 0 and less than 4 mm.
 15. The gas-phasereactor exhaust system of claim 13, wherein the channel forms asubstantially annular region around the susceptor.
 16. The gas-phasereactor exhaust system of claim 14, wherein the plenum comprises asubstantially hollow cylinder.
 17. The gas-phase reactor exhaust systemof claim 13, wherein a distance between the bottom portion of thesusceptor and the interior bottom surface of the reaction chamber isbetween about 2 mm and about 25 mm.
 18. The gas-phase reactor exhaustsystem of claim 13, further comprising a turbopump fluidly coupled tothe plenum.
 19. A gas-phase reactor system comprising: a gas-phasereactor comprising: a reaction chamber comprising a top surface, abottom surface, a sidewall, and an interior region formed between thetop surface, the bottom surface, and the sidewall; a susceptor withinthe interior region, the susceptor comprising a side perimeter; achannel formed between the side perimeter and the sidewall; and a plenumwithin the interior region and beneath the susceptor, the plenum fluidlycoupled to the channel; a vacuum source coupled to the plenum; and oneor more gas sources coupled to the gas-phase reactor.
 20. The gas-phasereactor system of claim 19, wherein a width of the channel is greaterthan 0 and less than 4 mm.